Setup pull request template

[uhooi]

Overview

Create .github/PULL_REQUEST_TEMPLATE.md .

References

• https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/creating-a-pull-request-template-for-your-repository
• https://github.com/cocoa-mhlw/cocoa/blob/v1.2.3/.github/PULL_REQUEST_TEMPLATE.md
• https://github.com/square/workflow-swift/blob/v1.0.0-beta.4/.github/PULL_REQUEST_TEMPLATE.md
• https://speakerdeck.com/niw/shi-jian-ios-opunsosupuroziekutofalseshi-mefang?slide=50
• https://speakerdeck.com/niw/shi-jian-ios-opunsosupuroziekutofalseshi-mefang?slide=51
• https://github.com/twitter/TwitterTextEditor/blob/master/.github/PULL_REQUEST_TEMPLATE.md

[github-actions[bot]]

👋 Thanks for reporting! Please PR :)